This invention relates to fluid handling and, more particularly, to fluid handling systems, e.g., pressure washers, of the self-proportioning type.
Pressure washers are widely known and widely used for such tasks as washing and wax-coating motor vehicles, preparing a building for painting, washing walkways and a host of similar tasks. Examples of pressure washers are disclosed in U.S. Pat. Nos. 5,409,032 (Berfield) and 5,718,255 (Gilpatrick et al.).
While pressure washers can be used with water alone (and are quite effective when so used), it is often desirable to mix a chemical product, e.g., a detergent, with water. The resulting solution is even more effective than plain water for certain purposes.
While certain types of pressure washers include a container for a chemical product, such pressure washers are disadvantageous for certain uses. Particularly, the user of the washer may, at different times, desire to use a detergent solution, an auto wax solution, a deck wash solution, as but a few examples. If the user desires to switch from one chemical product to another, it is preferred that the product container and all of the related tubing be first washed out with water. In other words, it is not a good idea (and may be self-defeating) to place an auto wax product into a container having detergent residue in it.
But insofar as is now known, there are no pressure washers which offer the product features and configuration which permit the user to quickly switch from one chemical product to another while yet avoiding diluting or impairing the quality of a product with residue from a previously-used product. And insofar as is now known, there is no selector valve suitable for use on such a pressure washer.
Another disadvantage of certain types of pressure washers arises from the mechanism used to control pump output pressure. A typical arrangement uses a pressure control knob which bypasses water in the pump. The knob is less than entirely convenient to use and its rotational position gives no indication of pressure or is only casually related thereto.
A multi-container pressure washer and related product selecting valve which addresses shortcomings of the prior art would be a distinct advance in the field of pressure washers.
It is an object of the invention to provide a multi-container pressure washer addressing shortcomings of prior art pressure washers.
Another object of the invention is to provide a multi-container pressure washer which permits a user to quickly switch between different chemical products.
Another object of the invention is to provide a multi-container pressure washer having a product selecting valve facilitating quickly switching between different chemical products.
Yet another object of the invention is to provide a multi-container pressure washer which includes an easy-to-use pressure control. How these and other objects are accomplished will become apparent from the following descriptions and from the drawings.
Aspects of the invention involve a pressure washer of the type including a wheeled chassis as well as a liquid pump, a pump-driving prime mover, and a liquid container, all supported by the chassis. The pump has a water inlet port and is coupled to a mixing device such as a venturi-type eductor mixer.
In the improvement, the washer has first and second containers and a product selecting valve, also supported by the chassis. Each of the containers is attached to a separate, i.e., first and second input or valve conduit extending to the valve. The valve is connected to an output or device conduit extending to the mixing device. In a specific, highly preferred embodiment, the pressure washer has a total of four containers, three for chemical products and one for fresh xe2x80x9cconduit rinse-outxe2x80x9d water.
To set up the pressure washer for use, a relatively small quantity of a different chemical is poured into each of the three chemical product containers. Herein, each such undiluted chemical is referred to as a xe2x80x9cconcentrate.xe2x80x9d A specified amount of water is then added to each such container (and to the chemical therein) and herein, each such moderately diluted substance is referred to as a xe2x80x9cproduct.xe2x80x9d The fourth container is filled only with water.
The multi-container, valve-equipped pressure washer permits the user to select (by valve manipulation) any one of several products, e.g., a detergent product, a car wash product, a deck wash product, an automobile wax product, or a multi-purpose cleaning product to be mixed with water from the pump. Herein, when a product is mixed with water from the pump, the resulting liquid delivered to the spray wand is referred to as a xe2x80x9csolution.xe2x80x9d The new pressure washer also permits the user to wash a product out of a conduit with fresh water from a separate water container before selecting another product to be mixed with the pumped water.
In more specific aspects of the invention, each of the containers includes a top fill neck and a neck cap or closure. The closures are xe2x80x9ctop-exposed,xe2x80x9d thereby providing free access to the containers closures for container filling. (Top-exposed closures means closures which are accessible without moving or removing any other component of the pressure washer.) And in a specific embodiment, the containers are of the same size and shape and the closures are in registry with the same horizontal plane.
In another aspect of the invention, the pressure washer has a third containerxe2x80x94and, most preferably, a fourth container. Each of the first, second and third containers includes a different chemical product. And the fourth container holds only water.
A highly preferred pressure washer has features which make the washer very easy to use. As examples, the washer has a control console with a product selector device and a pressure selector device mounted with respect to such console. In a specific embodiment, the product selector device is a rotary knob and the pressure selector device is a linearly-actuated lever controlling the throttle of the prime mover engine. On the console, the lever is identified by mnemonic symbols (e.g., L, M and H) and/or by graphic symbols related to pressure. (Since the pump rotates at engine speed, changing such engine speed will also change output pressure at the spray wand.)
In yet another aspect of the invention, the valve has a body with first, second, third and fourth inlet apertures formed in it. First, second, third and fourth conduits, respectively, are connected to such apertures. The valve body also has an outlet aperture having a device conduit attached to it and extending from the outlet aperture to the mixing device. A distributor is mounted for movement, e.g., sliding or rotary movement, with respect to the valve body and has a channel for selectively connecting one of the conduits to the device conduit.
When the distributor is set to connect a particular inlet conduit to the device conduit, it is preferred that the distributor be restrained from moving from the selected position. To that end, the valve includes a position retention mechanism coacting between the distributor and the valve body. In an exemplary embodiment, the position retention mechanism includes a plurality of shallow detent pockets and a pocket engagement member, e.g. a ball or the like, which is spring biased toward the pockets.
In more specific aspects of the invention, the distributor is mounted for rotational movement about an axis of rotation. The first, second, third and fourth inlet apertures extend along first, second, third and fourth aperture axes, respectively. Such aperture axes have a fixed positional relationship with respect to the axis of rotation. In a highly preferred embodiment, such positional relationship of the aperture axes to the axis of rotation is substantially parallel thereto.
More particularly, such aperture axes define an arc of a circle. The outlet aperture extends along an outlet axis coincident with the circle center. (It is to be appreciated that in other valve embodiments involving, for example, a rotary or linearly sliding distributor, the positional relationship of the aperture axes to the axis of rotation may be angular thereto.
Yet other aspects of the invention involve additional features of the product selecting valve. As to one such feature, the valve has a dynamic sealing surface coacting between the body and the distributor. At least the first aperture axis is substantially parallel to the axis of rotation and the sealing surface is on an O-ring lodged between the body and the distributor. Such O-ring extends around the first aperture axis.
Other details of the invention are set forth in the following detailed description and in the drawings.